Answer: number 7. 7
Step-by-step explanation:
Simplifying
7X + 1 + -5X = 15
Reorder the terms:
1 + 7X + -5X = 15
Combine like terms: 7X + -5X = 2X
1 + 2X = 15
Solving
1 + 2X = 15
Solving for variable 'X'.
Move all terms containing X to the left, all other terms to the right.
Add '-1' to each side of the equation.
1 + -1 + 2X = 15 + -1
Combine like terms: 1 + -1 = 0
0 + 2X = 15 + -1
2X = 15 + -1
Combine like terms: 15 + -1 = 14
2X = 14
Divide each side by '2'.
X = 7
Simplifying
X = 7
